The clamping together of composite sections, with C-shaped grooves on their longitudinal side to form a compound joint, in particular of metal, is known. This type of joint is used in the manufacture of several types of products including window frames, cargo sections of trucks, and vehicular chassis. This type of union cannot transmit shear or thrust forces in the longitudinal direction. Often, additional techniques such as adding fasteners, using adhesives, or crimping to increase the strength of the joint and allow the union to transmit shear or thrust forces in the longitudinal direction are employed in constructing such a joint.
These additional techniques have various disadvantages. The use of additional fasteners such as screws causes weakening of the joint due to the removal of material by machining. In order to use adhesives, very clean surfaces and considerable drying times must be provided. Crimping the joint requires additional expensive machining. For certain section forms, particularly those with concealed contact faces, these additional joining techniques can only be carried out with great difficulty.
It is an object of the present invention to avoid these disadvantages and to provide composite elongated sections for forming a compound joint as well as a method for the joining of sections, which makes possible a simple, high-strength union of elongated sections, particularly at inaccessible contact faces.